Check out the companies making headlines after the bell Monday:
Gap - The retailer said it will close 26 percent of its North American namesake stores over the next several years in an effort to streamline its store fleet. Shares rose more than 1 percent after the announcement.
Under Armour - The athletic apparel maker created a new, non-voting class of common stock. Under Armour plans to issue the new class C stock to all current stockholders, which will have the same effect as a two-for-one stock split, the company said. Shares rose modestly after hours.
IMAX - The entertainment provider said IMAX box office sales for Universal Pictures' "Jurassic World" were a record-setting $23.2 million, beating the previous best of $16.7 million. That helped send shares nearly 1 percent higher during the regular session. They gave up those gains after hours. (Disclosure: Universal Pictures is a subsidiary of NBCUniversal, CNBC's parent company.)